1. Field of the Invention
The present invention relates to a dye-containing negative curable composition suitable for forming a color filter used for liquid crystal display devices and solid-state image pickup devices, a dye-containing color filter and a method for producing the same.
2. Related Art
Known methods for producing a color filter used for liquid crystal display devices (LCD) and solid state image pick-up devices (CCD, CMOS, etc.) include a dying method, printing method, electrodeposition method and pigment dispersion method.
Of these methods, the pigment dispersion method is a method for producing the color filter by a photolithographic method using a colored radiation-sensitive composition in which a pigment is dispersed in various photosensitive compositions. Since a pigment is used as a colorant, the method is advantageous in stability against light and heat. In addition, positional accuracy is high since the filter is patterned by the photolithographic method, and the method has been widely used for favorably producing a color filter for highly precise color displays having a large screen size.
When the color filter is produced by the pigment dispersion method, a coating film is formed by applying a radiation sensitive composition with a spin coater or roll coater followed by drying on glass substrate, colored pixels are formed by patterned exposure and development of the coating film, and the color filter is obtained by repeating this procedure for each color depending on the number of hues. Known examples of such pigment dispersion method include using a negative photosensitive composition in which a photopolymerizable monomer and a photopolymerization initiator are used together in an alkali-soluble resin (for example, see Japanese Patent Application Laid-Open (JP-A) Nos. 2-199403, 4-76062, 5-273411, 6-184482 and 7-140654).
On the other hand, the color filter for the solid state image pickup device has been required to be further fine and precise. However, it is difficult to attempt to further improve resolution in the conventional pigment dispersion system, since color unevenness tends to appear due to a relatively coarse particle diameter of the pigment. Accordingly, the pigment dispersion method has not been suitable for the uses such as the solid state image pick-up device (CCD) in which fine patters are required.
In view of the above-mentioned problems, a method using a dye in place of the pigment has been proposed as a solving method (for example, see JP-A No. 2005-99488).
In view of the above-mentioned problems, a technique using an organic solvent-soluble dye (may be simply referred to the “dye” hereinafter) in place of the pigment has been proposed as another solving method (for example, see JP-A No. 2005-99488).
In another technique for producing the colored photosensitive resin composition containing a dye, the moisture content in the composition is restricted within a specified range in order to suppress minute patterns after development from being peeled and to suppress incidence of penetration of the patterns into the substrate form appearing (for example, see JP-A No. 2003-29542).
The composition containing the dye is usually poor in light resistance as compared with the composition containing the pigment. For improving light resistance, an alcohol-soluble Ni or Co compound or a transition metal complex is added in vitreous colored filters (see, for example, Japanese Patent No. 2986796, and JP-A Nos. 11-223720 and 2004-295116).